This invention relates to removing articles from a blow molding machine and more particularly to apparatus for removing articles from a vertical, wheel blow molding machine of the type wherein the mold sections close and open parallel to the wheel axis.
In the past, blown articles have been individually removed in finished or semi-finished (i.e. with waste flash still attached) form from the discharge area of wheel blow molding machines by gravity ejection onto a chute feeding a conveyor supplying a surge hopper. An operation at the hopper outlet then usually manually fed the articles to the next downstream work station, such as a trimming machine. If the articles could be mechanically controlled during removal from the molding machine such that they could be forwarded directly to the next work station, manpower could be reduced and the hopper bypassed. Also, forwarding directly from the molding machine to the trimming machine insures a more uniform temperature of the plastic at the time of trimming and therefore a more uniformly trimmed article.
U.S. Pat. No. 3,770,098 discloses removal of containers from molds of a wheel machine of the type using hinged book molds wherein one section is rigidly mounted on a support and the other is pivotally attached thereto for opening and closing the mold.
An equally commercially popular wheel blow molding machine utilizes molds wherein each section simultaneously moves horizontally parallel to the machine axis during opening and closing. This type of movement has the advantage over other forms of evenly contacting the hot, tangentially fed parison with both sections of the closing mold at the same time, thus avoiding any uneven chilling effects which can occur when one portion of the mold contacts the parison appreciably ahead of another. With this type of machine employing horizontally operating molds, the formed part, just prior to release for gravity ejection from the machine, is conventionally suspended momentarily on the mold parting line in the mold-open portion of the machine periphery between a pair of article knockout pins while fully out of engagement with the recessed portions of each section. A more complete description of this type of machine is set forth, for example, in U.S. Pat. Nos. 3,218,669, 3,365,748 and 3,764,250.
Sequential removal of molded articles individually separated from each other in a controlled manner from a machine of the type referred to has, however, not been done, as far as is known, the system of the aforementioned 3,770,098 patent presenting substantial clearance problems between the arcuately downwardly descending arms of the system therein disclosed and the continuously moving mold sections of the machine.
In addition, and as set forth in detail in the aforementioned 3,764,250 patent, the continuously moving molds of the machine therein described capture portions of an upwardly extruding parison at about an eight-nine o'clock position and discharge the blown articles downwardly some 270.degree.later at about a five-six o'clock position. With this machine geometry, the article discharge area is especially crowded since it is well within the confines of the machine proper and has dictated the use of a conveyor moving tangential to the circular path of mold travel to transport the gravity-discharged articles away on their sides in a relatively uncontrolled manner with respect to positional orientation thereof on the conveyor surface.